Europe's flora becoming more homogeneous

Published: Sunday, December 13, 2009, 15:40 [IST]

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Washington, December 13 (ANI): In a new research, scientists have determined that due to more plant introductions than extinctions, plant communities of many European regions are becoming more homogeneous, and thereby losing the ability to react to environmental changes.

According to the findings, the same species are occurring more frequently, whereas rare species are becoming extinct.

It is not only the biological communities that are becoming increasingly similar, but also the phylogenetic relations between regions.

These processes have led to a loss of uniqueness among European floras.

For their research, the scientists analysed the data of flora native to Europe (Flora Europaea), extinct plant species (national red lists) and alien plant species from the DAISIE database.

The researchers also took into account those European plants that are native to a particular region of Europe but considered as introduced species in another.

It works in a similar way for the species considered to be "extinct".

While in the whole of Europe only 2 plant species can "really" be considered as extinct, approx. 500 species have become locally extinct.

One such example is the Blue Woodruff, a weed that grows on cultivated land, which has been greatly displaced particularly from the intensification of agricultural practices.

This species is considered to be locally extinct in Germany and Austria for example, whereas it still occurs in Italy and Spain.

The researchers were able to demonstrate, that biodiversity is increasing in all regions of Europe due to high numbers of alien species.

But at the same time, the plant communities of the regions are becoming increasingly more homogenous because alien species are distributed relatively consistently over the continent.

If one finds many very similar looking trees, then one assumes that the flexibility of the communities is no longer as high to be able to react positively to these changes.

According to the researchers, biological depletion from loss of species and introduced species is a consequence of global change associated with increasing pressure on the environment.

"Our studies have shown that in spite of an increase in regional species richness due to species introductions exceeding the local extinctions of plant species in European regions, these are increasingly losing both their phylogenetic and taxonomic uniqueness," said Dr. Marten Winter from the Helmholtz Center for Environmental Research (UFZ). (ANI)